1. Field of the Invention
The present invention relates generally to a seedling with soil selecting and transporting apparatus for a transplanting machine which automatically transplants seedlings with soil to a farm field. The seedlings with soil may be paper potted seedlings grown in a cardboard tube, or potted seedlings grown in a pot or a tray, for example. More specifically, the invention relates to a seedling with soil selecting and transporting apparatus for a transplanting machine which can select good seedlings with soil having leaf portions grown to a normal length, and no good seedlings with soil having leaf portions not grown to the normal length or having no leaf.
2. Description of the Related Art
Japanese Examined Utility Model Publication No. 2-29843 discloses a seedling with soil selecting and transporting apparatus for a transplanting machine of the type set forth above.
FIG. 7 shows the seedling with soil selecting and transporting apparatus for the transplanting machine disclosed in the above-identified publication. As shown in FIG. 7, arbitrarily arranged along a transport path are a seedling selecting and transporting conveyer 1 for selecting good paper potted seedlings P having leaf portions P1 grown to a normal length, and no good paper potted seedlings P' having leaf portions P1' not grown to the normal length, a seedling supply conveyer supplying the good and no good paper potted seedlings P and P' to the seedling selecting and transporting conveyer 1, a transporting conveyer 2, and a seedling aligning and transporting conveyer 3 transporting the selected good paper potted seedlings P to a seedling planting mechanism.
Each of the foregoing conveyers 1 to 3 is constructed by stretching a plurality of round string belts 10 between parallel pulleys 4 to 9. In addition to the pulleys and round string belts, the seedling selecting and transporting conveyer 1 includes a belt 11 with a wing strip, one strip form belt 12 mounting soil depositing portions P2, P2' of the good and no good paper potted seedlings P and P', and a pair of wide belts 13 and 14 arranged for clamping, from the upper and lower sides thereof, only leaf portions P1 of the good paper potted seedlings P, namely the leaf portions P1 grown to the normal length.
Selection of the good paper potted seedlings P and the no good paper potted seedlings P' by the seedling selecting and transporting conveyer 1 is performed by mounting the soil depositing portions P2 and P2' of the good paper potted seedlings P and the no good paper potted seedlings P' on one strip form belt 12, as shown in FIG. 8.
Namely, when a paper potted seedling transported is a good paper potted seedling P, it is transported in the condition wherein it is fallen sideways with its leaf portion clamped by a pair of upper and lower wide belts 13 and 14. On the other hand, when a paper potted seedling transported is a no good paper potted seedling P', it falls down into a hollow space 1a since the wide belts 13 and 14 cannot clamp the leaf portion.
However, the conventional seedling with soil selecting and transporting apparatus is constructed by exposing the pulleys 4, to 9, around which the round string belts 10 and the belt 11 with the wing strip are mounted. With such an arrangement, a clump of earth may deposit on the pulley thereby easily causing the round string belts to move off the pulleys. Furthermore, since each of the conveyers 1 to 3 are formed by a combination of the pulleys and the round string belts, construction is complicated.
Also, in the seedling selecting and transporting conveyer 1, selective transportation is performed in the condition wherein the seedling is fallen sideways with the soil depositing portion mounted on one strip form belt 12 and the leaf portion P1 of the good paper potted seedling P clamped by the wide belts 13 and 14. With such an arrangement, balance may be easily destroyed even by slight offset of the position of the soil depositing portion P2 mounted on the strip form belt 12. For example, even by vibration associated with traveling of the transporting machine, the soil depositing portion P2 may slip off the strip form belt 12 thereby placing the seedling in an outwardly drooped condition. Furthermore, the tendency to destroy balance becomes higher for shorter length of the soil depositing portion P2.
In the condition where the soil depositing portion P2 droops outwardly from the strip form belt 12, a good paper potted seedling P is still transported with its the leaf portion P1 clamped between the wide belts 13 and 14. Therefore, when a good paper potted seedling P is transferred from the seedling selecting and transporting conveyer 1 to the transfer conveyer 2, the drooping soil depositing portion P2 collides with the pulley 6, or the like, of the transfer conveyer 2 to potentially cause difficulty in transfer to the transfer conveyer 2.
Furthermore, even when the good paper potted seedlings P having a dropping soil deposition portion P2 can be transferred to the transfer conveyer 2, the soil depositing portion P2 may collide on the pulley 6, or the like of the transfer conveyer 2 thereby causing delay of the transfer timing of the soil depositing portion P2 from the transfer timing of the leaf portion P1. In other words, the leaf portion P1 of a good paper potted seedling P is transferred in an attitude wherein its leaf portion is tilted toward the downstream side in the transporting direction in relation to its soil depositing portion P2. Thus, the good paper potted seedling P contacts with other good paper potted seedlings transferred preceding and following the objective good paper potted seedling thereby possibly disturbing alignment. This results in a difficult transplanting operation.